As is known in the art, feed structures are used to couple a radar or communication system to an array of antenna elements. One component of a feed structure is a circulator. U.S. patent application Ser. No. 13/952,020 entitled “Dual Stripline Tile Circulator Utilizing Thick Film Post-Fired Substrate Stacking”, which is incorporated by reference, describes a dual stacked stripline circulator that includes multiple composite ferrite discs, each having an inner portion and an outer portion; a first substrate having an edge with a first composite ferrite disc disposed in the first substrate; a second substrate having an edge with a second composite ferrite disc disposed in the second substrate; a third substrate having an edge with a third composite ferrite disc disposed in the third substrate, the third substrate disposed adjacent the second substrate; a fourth substrate having an edge with a fourth composite ferrite disc disposed in the fourth substrate; a first pattern defining three ports of a first three-port circulator disposed between the first substrate and the second substrate; a second pattern defining three ports of a second three-port circulator disposed between the third substrate and the fourth substrate; and a metal film encircling the edge of the first, second, third and fourth substrate. The teachings of U.S. patent application Ser. No. 13/952,020 describe the advantages of such a configuration.